From da5bab079f9b7d90ba234965a14914ace55e45e9 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sat, 8 Jun 2013 12:56:03 +0200 Subject: net: udp4: move GSO functions to udp_offload Similarly to TCP offloading and UDPv6 offloading, move all related UDPv4 functions to udp_offload.c to make things more explicit. Also, by this, we can make those functions static. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- net/ipv4/udp_offload.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 net/ipv4/udp_offload.c (limited to 'net/ipv4/udp_offload.c') diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c new file mode 100644 index 000000000000..f35eccaa855e --- /dev/null +++ b/net/ipv4/udp_offload.c @@ -0,0 +1,100 @@ +/* + * IPV4 GSO/GRO offload support + * Linux INET implementation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * UDPv4 GSO support + */ + +#include +#include +#include + +static int udp4_ufo_send_check(struct sk_buff *skb) +{ + if (!pskb_may_pull(skb, sizeof(struct udphdr))) + return -EINVAL; + + if (likely(!skb->encapsulation)) { + const struct iphdr *iph; + struct udphdr *uh; + + iph = ip_hdr(skb); + uh = udp_hdr(skb); + + uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, + IPPROTO_UDP, 0); + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + skb->ip_summed = CHECKSUM_PARTIAL; + } + + return 0; +} + +static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, + netdev_features_t features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + unsigned int mss; + + mss = skb_shinfo(skb)->gso_size; + if (unlikely(skb->len <= mss)) + goto out; + + if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { + /* Packet is from an untrusted source, reset gso_segs. */ + int type = skb_shinfo(skb)->gso_type; + + if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY | + SKB_GSO_UDP_TUNNEL | + SKB_GSO_GRE | SKB_GSO_MPLS) || + !(type & (SKB_GSO_UDP)))) + goto out; + + skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); + + segs = NULL; + goto out; + } + + /* Fragment the skb. IP headers of the fragments are updated in + * inet_gso_segment() + */ + if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL) + segs = skb_udp_tunnel_segment(skb, features); + else { + int offset; + __wsum csum; + + /* Do software UFO. Complete and fill in the UDP checksum as + * HW cannot do checksum of UDP packets sent as multiple + * IP fragments. + */ + offset = skb_checksum_start_offset(skb); + csum = skb_checksum(skb, offset, skb->len - offset, 0); + offset += skb->csum_offset; + *(__sum16 *)(skb->data + offset) = csum_fold(csum); + skb->ip_summed = CHECKSUM_NONE; + + segs = skb_segment(skb, features); + } +out: + return segs; +} + +static const struct net_offload udpv4_offload = { + .callbacks = { + .gso_send_check = udp4_ufo_send_check, + .gso_segment = udp4_ufo_fragment, + }, +}; + +int __init udpv4_offload_init(void) +{ + return inet_add_offload(&udpv4_offload, IPPROTO_UDP); +} -- cgit v1.2.3